Serum leptin levels in pregnant women with type 1 diabetes mellitus

Abstract

Leptin is an important weight regulator and during pregnancy leptin is not only synthesized in adipose tissue but also in the placenta.To examine changes in serum leptin levels in women with type 1 diabetes mellitus during pregnancy and post delivery in relation to concomitant changes in maternal body weight, birth weight, glycemic control, and blood pressure.Non-fasting serum leptin from 45 women with type 1 diabetes mellitus were studied consecutively throughout pregnancy and 3 months post partum.Serum leptin was positively associated with HbA1c in week 18, 22 and 30 (r=0.38, 0.41, and 0.54, respectively, p<0.05, adjusted for body weight). Moreover, serum leptin correlated positively with maternal body weight and BMI (0.45<r<0.66, p<0.05). Serum leptin was significantly lower after delivery than during pregnancy where the levels showed no change from gestational week 14 to week 38. In obese women (BMI >25 kg/m2), the changes during pregnancy and the level of serum leptin were significantly greater compared to lean women (p<0.05). The women with low ambulatory blood pressure (lower tertile, mean arterial blood pressure <83.4 mmHg) showed the lowest level of serum leptin throughout pregnancy and it changed significantly differently from the women with higher blood pressure (p<0.05).Changes in serum leptin levels of pregnant women with type 1 diabetes mellitus were associated with parallel changes in maternal body weight and glycemic control. Women with low blood pressure had the lowest serum leptin levels throughout pregnancy.